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Gilchrist G, Dheensa S, Johnson A, Henderson J, Radcliffe P, Dwyer G, Turner R, Thomson K, Papastavrou Brooks C, Love B, Zenasni Z, Berbary C, Carter B, Parrott S, Li J, Easton C, Bergman C, Feder G, Gilchrist E. Adapting the ADVANCE group program for digitally-supported delivery to reduce intimate partner violence by men in substance use treatment: a feasibility study. Front Psychiatry 2024; 14:1253126. [PMID: 38328518 PMCID: PMC10847362 DOI: 10.3389/fpsyt.2023.1253126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 12/27/2023] [Indexed: 02/09/2024] Open
Abstract
Introduction COVID-19 restrictions created barriers to "business as usual" in healthcare but also opened the door to innovation driven by necessity. This manuscript (1) describes how ADVANCE, an in-person group perpetrator program to reduce intimate partner violence (IPV) against female (ex)partners by men in substance use treatment, was adapted for digitally-supported delivery (ADVANCE-D), and (2) explores the feasibility and acceptability of delivering ADVANCE-D to men receiving substance use treatment. Methods Firstly, the person-based approach and mHealth development framework were used to iteratively adapt ADVANCE for digitally-supported delivery including conceptualization, formative research, and pre-testing. Then, a non-randomized feasibility study was conducted to assess male participants' eligibility, recruitment, and attendance rates and uptake of support offered to their (ex)partners. Exploratory analyses on reductions in IPV perpetration (assessed using the Abusive Behavior Inventory; ABI) and victimization (using the revised ABI; ABI-R) at the end of the program were performed. Longitudinal qualitative interviews with participants, their (ex)partners, and staff provided an understanding of the program's implementation, acceptability, and outcomes. Results The adapted ADVANCE-D program includes one goal-setting session, seven online groups, 12 self-directed website sessions, and 12 coaching calls. ADVANCE-D includes enhanced risk management and support for (ex)partners. Forty-five participants who had perpetrated IPV in the past 12 months were recruited, forty of whom were offered ADVANCE-D, attending 11.4 (SD 9.1) sessions on average. Twenty-one (ex)partners were recruited, 13 of whom accepted specialist support. Reductions in some IPV perpetration and victimization outcome measures were reported by the 25 participants and 11 (ex)partners interviewed pre and post-program, respectively. Twenty-two participants, 11 (ex)partners, 12 facilitators, and 7 integrated support service workers were interviewed at least once about their experiences of participation. Overall, the program content was well-received. Some participants and facilitators believed digital sessions offered increased accessibility. Conclusion The digitally-supported delivery of ADVANCE-D was feasible and acceptable. Remote delivery has applicability post-pandemic, providing greater flexibility and access. Given the small sample size and study design, we do not know if reductions in IPV were due to ADVANCE-D, time, participant factors, or chance. More research is needed before conclusions can be made about the efficacy of ADVANCE-D.
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Affiliation(s)
- Gail Gilchrist
- National Addiction Center, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Sandi Dheensa
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Amy Johnson
- School of Health in Social Science, Department of Clinical Psychology, Center for Psychological Therapies, University of Edinburgh, Edinburgh, United Kingdom
| | - Juliet Henderson
- National Addiction Center, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Polly Radcliffe
- National Addiction Center, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Georges Dwyer
- National Addiction Center, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Richard Turner
- National Addiction Center, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Kate Thomson
- School of Health in Social Science, Department of Clinical Psychology, Center for Psychological Therapies, University of Edinburgh, Edinburgh, United Kingdom
| | - Cat Papastavrou Brooks
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Beverly Love
- National Addiction Center, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Zohra Zenasni
- Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Cassandra Berbary
- College of Health Sciences and Technology, Rochester Institute of Technology, Rochester, NY, United States
| | - Ben Carter
- National Addiction Center, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Steve Parrott
- Department of Health Sciences, University of York, York, United Kingdom
| | - Jinshuo Li
- Department of Health Sciences, University of York, York, United Kingdom
| | - Caroline Easton
- College of Health Sciences and Technology, Rochester Institute of Technology, Rochester, NY, United States
| | | | - Gene Feder
- Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Elizabeth Gilchrist
- School of Health in Social Science, Department of Clinical Psychology, Center for Psychological Therapies, University of Edinburgh, Edinburgh, United Kingdom
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Magbagbeola M, Rai ZL, Doyle K, Lindenroth L, Dwyer G, Gander A, Stilli A, Davidson BR, Stoyanov D. An adaptable research platform for ex vivo normothermic machine perfusion of the liver. Int J Comput Assist Radiol Surg 2023:10.1007/s11548-023-02903-4. [PMID: 37095316 DOI: 10.1007/s11548-023-02903-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 03/31/2023] [Indexed: 04/26/2023]
Abstract
PURPOSE This paper presents an assessment of a low-cost organ perfusion machine designed for use in research settings. The machine is modular and versatile in nature, built on a robotic operating system (ROS2) pipeline allowing for the addition of specific sensors for different research applications. Here we present the system and the development stages to achieve viability of the perfused organ. METHODS The machine's perfusion efficacy was assessed by monitoring the distribution of perfusate in livers using methylene blue dye. Functionality was evaluated by measuring bile production after 90 min of normothermic perfusion, while viability was examined using aspartate transaminase assays to monitor cell damage throughout the perfusion. Additionally, the output of the pressure, flow, temperature, and oxygen sensors was monitored and recorded to track the health of the organ during perfusion and assess the system's capability of maintaining the quality of data over time. RESULTS The results show the system is capable of successfully perfusing porcine livers for up to three hours. Functionality and viability assessments show no deterioration of liver cells once normothermic perfusion had occurred and bile production was within normal limits of approximately 26 ml in 90 min showing viability. CONCLUSION The developed low-cost perfusion system presented here has been shown to keep porcine livers viable and functional ex vivo. Additionally, the system is capable of easily incorporating several sensors into its framework and simultaneously monitor and record them during perfusion. The work promotes further exploration of the system in different research domains.
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Affiliation(s)
- M Magbagbeola
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), University College London, London, UK.
| | - Z L Rai
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), University College London, London, UK
- Centre for Surgical Innovation, Organ Repair and Transplantation (CSIORT), UCL, London, UK
- Royal Free Hospital NHS Trust, London, UK
| | - K Doyle
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), University College London, London, UK
| | - L Lindenroth
- Department of Surgical and Interventional Engineering, School of Biomedical Engineering and Imaging Sciences, King's College London, London, UK
| | - G Dwyer
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), University College London, London, UK
| | - A Gander
- Centre for Surgical Innovation, Organ Repair and Transplantation (CSIORT), UCL, London, UK
- Royal Free Hospital NHS Trust, London, UK
| | - A Stilli
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), University College London, London, UK
| | - B R Davidson
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), University College London, London, UK
- Centre for Surgical Innovation, Organ Repair and Transplantation (CSIORT), UCL, London, UK
- Royal Free Hospital NHS Trust, London, UK
| | - D Stoyanov
- Wellcome/EPSRC Centre for Interventional and Surgical Sciences (WEISS), University College London, London, UK
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Magbagbeola M, Doyle K, Rai ZL, Lindenroth L, Dwyer G, Stilli A, Davidson BR, Stoyanov D. Evaluation of A Novel Organ Perfusion Research Platform. Annu Int Conf IEEE Eng Med Biol Soc 2022; 2022:2565-2568. [PMID: 36086012 DOI: 10.1109/embc48229.2022.9871028] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
This paper presents a novel, low cost, organ perfusion machine designed for use in research. The modular and versatile nature of the system allows for additional sensing equipment to be added or adapted for specific use. Here we introduce the system and present its preliminary evaluation by assessing its ability to maintain a predetermined input pressure. A proportional-integral-derivative (PID) controller was implemented and tested on a porcine liver to maintain input pressure to the hepatic artery and compared to bench tests. The results confirmed the effectiveness of the controller for maintaining input through the hepatic artery (HA) in a timely manner. Clinical Relevance-Machine Perfusion (MP) is proving to be an invaluable adjunct in clinical practice. With its ongoing success in the transplant arena, we propose MP for use in research. A cost-effective, versatile system that can be modified for specific research use to test new pharmacological therapies, imaging techniques or develop simulation training would be beneficial.
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Hudson AI, Fleming-Davies AE, Páez DJ, Dwyer G. Genotype-by-genotype interactions between an insect and its pathogen. J Evol Biol 2016; 29:2480-2490. [PMID: 27622965 DOI: 10.1111/jeb.12977] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 08/31/2016] [Accepted: 09/02/2016] [Indexed: 12/22/2022]
Abstract
Genotype-by-genotype (G×G) interactions are an essential requirement for the coevolution of hosts and parasites, but have only been documented in a small number of animal model systems. G×G effects arise from interactions between host and pathogen genotypes, such that some pathogen strains are more infectious in certain hosts and some hosts are more susceptible to certain pathogen strains. We tested for G×G interactions in the gypsy moth (Lymantria dispar) and its baculovirus. We infected 21 full-sib families of gypsy moths with each of 16 isolates of baculovirus and measured the between-isolate correlations of infection rate across host families for all pairwise combinations of isolates. Mean infectiousness varied among isolates and disease susceptibility varied among host families. Between-isolate correlations of infection rate were generally less than one, indicating nonadditive effects of host and pathogen type consistent with G×G interactions. Our results support the presence of G×G effects in the gypsy moth-baculovirus interaction and provide empirical evidence that correlations in infection rates between field-collected isolates are consistent with values that mathematical models have previously shown to increase the likelihood of pathogen polymorphism.
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Affiliation(s)
- A I Hudson
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
| | - A E Fleming-Davies
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
| | - D J Páez
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
| | - G Dwyer
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
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Abstract
Investment in host defences against pathogens may lead to trade-offs with host fecundity. When such trade-offs arise from genetic correlations, rates of phenotypic change by natural selection may be affected. However, genetic correlations between host survival and fecundity are rarely quantified. To understand trade-offs between immune responses to baculovirus exposure and fecundity in the gypsy moth (Lymantria dispar), we estimated genetic correlations between survival probability and traits related to fecundity, such as pupal weight. In addition, we tested whether different virus isolates have different effects on male and female pupal weight. To estimate genetic correlations, we exposed individuals of known relatedness to a single baculovirus isolate. To then evaluate the effect of virus isolate on pupal weight, we exposed a single gypsy moth strain to 16 baculovirus isolates. We found a negative genetic correlation between survival and pupal weight. In addition, virus exposure caused late-pupating females to be identical in weight to males, whereas unexposed females were 2-3 times as large as unexposed males. Finally, we found that female pupal weight is a quadratic function of host mortality across virus isolates, which is likely due to trade-offs and compensatory growth processes acting at high and low mortality levels, respectively. Overall, our results suggest that fecundity costs may strongly affect the response to selection for disease resistance. In nature, baculoviruses contribute to the regulation of gypsy moth outbreaks, as pathogens often do in forest-defoliating insects. We therefore argue that trade-offs between host life-history traits may help explain outbreak dynamics.
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Affiliation(s)
- D J Páez
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
| | - A E Fleming-Davies
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
| | - G Dwyer
- Department of Ecology and Evolution, University of Chicago, Chicago, IL, USA
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Abstract
Most mathematical models of disease assume that transmission is linearly dependent on the densities of host and pathogen. Recent data for animal diseases, however, have cast doubt on this assumption, without assessing the usefulness of alternative models. In this article, we use a combination of laboratory dose-response experiments, field transmission experiments, and observations of naturally occurring populations to show that virus transmission in gypsy moths is a nonlinear function of virus density, apparently because of heterogeneity among individual gypsy moth larvae in their susceptibility to the virus. Dose-response experiments showed that larvae from a laboratory colony of gypsy moths are substantially less heterogeneous in their susceptibility to the virus than are larvae from feral populations, and field experiments showed that there is a more strongly nonlinear relationship between transmission and virus density for feral larvae than for lab larvae. This nonlinearity in transmission changes the dynamics of the virus in natural populations so that a model incorporating host heterogeneity in susceptibility to the virus gives a much better fit to data on virus dynamics from large-scale field plots than does a classical model that ignores host heterogeneity. Our results suggest that heterogeneity among individuals has important effects on the dynamics of disease in insects at several spatial and temporal scales and that heterogeneity in susceptibility may be of general importance in the ecology of disease.
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Affiliation(s)
- G Dwyer
- Department of Entomology, Fernald Hall, University of Massachusetts, Amherst, Massachusetts 01003-2410, USA
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Abstract
Although coevolution is complicated, in that the interacting species evolve in response to each other, such evolutionary dynamics are amenable to mathematical modeling. In this article, we briefly review models and data on coevolution between plants and the pathogens and herbivores that attack them. We focus on "arms races," in which trait values in the plant and its enemies escalate to more and more extreme values. Untested key assumptions in many of the models are the relationships between costs and benefits of resistance in the plant and the level of resistance, as well as how costs of virulence or detoxification ability in the enemy change with levels of these traits. A preliminary assessment of these assumptions finds only mixed support for the models. What is needed are models that are more closely tailored to particular plant-enemy interactions, as well as experiments that are expressly designed to test existing models.
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Affiliation(s)
- J Bergelson
- Department of Ecology and Evolution, University of Chicago, Chicago, Illinois 60637, USA.
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Abstract
Hybrid zones that result in the genetic assimilation (replacement) of one species by another are underrepresented in the animal literature, most likely due to their transient nature. One such zone involves the rusty crayfish, Orconectes rusticus, and its congener O. propinquus. Orconectes rusticus was recently introduced into northern Wisconsin and Michigan lakes and streams, where it is hybridizing with and displacing resident O. propinquus. Here we report on a study investigating the dynamics of a hybrid zone between the two crayfish in Trout Lake, Wisconsin, where both the time (circa 1979) and location of the initial introduction are known. Our prediction was that hybridization should hasten the demise of O. propinquus because we expected that male O. rusticus (which are larger than congeners) would outcompete male O. propinquus for mates of both species. If hybrid progeny are unfit, then the result would be decreased reproductive output of O. propinquus females. However, we found a pattern of cytonuclear disequilibrium between allozymes and mtDNA suggesting that a majority (94.5%) of F1 hybrids resulted from matings between O. rusticus females and O. propinquus males. Also contrary to expectations, fecundity (O. rusticus and O. propinquus) and early hybrid survivorship did not differ significantly from nonhybrids. Moreover, adults of mixed ancestry were superior to both O. rusticus and O. propinquus in competition for a limiting food resource. Using a single-locus model, we estimated that hybridization increases the advance of O. rusticus genes in Trout Lake between 4.8% and 36.3% above that due to the previously documented ecological interactions. Consequently, whereas hybridization may be hastening the elimination of genetically pure O. propinquus, introgression is nevertheless slowing the loss of O. propinquus nuclear genes. Although our results suggest that O. rusticus and O. propinquus may not be true species under the biological concept, their ecological differences are of great conservation importance.
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Affiliation(s)
- W L Perry
- Department of Biological Sciences, Illinois State University, Normal 61790-4120, USA.
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Darby D, Bischof J, Cutter G, de Vernal A, Hillaire-Marcel C, Dwyer G, McManus J, Osterman L, Polyak L, Poore R. New record shows pronounced changes in Arctic Ocean circulation and climate. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/01eo00345] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
The co-evolutionary 'arms race' is a widely accepted model for the evolution of host-pathogen interactions. This model predicts that variation for disease resistance will be transient, and that host populations generally will be monomorphic at disease-resistance (R-gene) loci. However, plant populations show considerable polymorphism at R-gene loci involved in pathogen recognition. Here we have tested the arms-race model in Arabidopsis thaliana by analysing sequences flanking Rpm1, a gene conferring the ability to recognize Pseudomonas pathogens carrying AvrRpm1 or AvrB. We reject the arms-race hypothesis: resistance and susceptibility alleles at this locus have co-existed for millions of years. To account for the age of alleles and the relative levels of polymorphism within allelic classes, we use coalescence theory to model the long-term accumulation of nucleotide polymorphism in the context of the short-term ecological dynamics of disease resistance. This analysis supports a 'trench warfare' hypothesis, in which advances and retreats of resistance-allele frequency maintain variation for disease resistance as a dynamic polymorphism.
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Affiliation(s)
- E A Stahl
- Committee on Genetics, University of Chicago, Illinois 60637, USA
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Dwyer G, Dwyer E, Hammerle T. TRADITIONAL VERSUS OVER-THE-HEAD SIT AND REACH TESTING METHODOLOGIES FOR LOW BACK-HAMSTRING FLEXIBILITY. Med Sci Sports Exerc 1999. [DOI: 10.1097/00005768-199905001-01568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
We have cloned and sequenced cDNA transcribed from the 3' 1,239 nucleotides of the genomic RNA of a Western Australian isolate (MI) of bean yellow mosaic potyvirus (BYMV). This sequence contains 246 nucleotides of the NIb (replicase) gene and 819 nucleotides representing the entire coding region of the viral coat protein gene, followed by a 3' non-coding region of 174 nucleotides. The coding region of the coat protein gene is identical in length (273 amino acids) to that already reported for other isolates of this virus. The sequence identities obtained for BYMV-MI and published sequences of BYMV isolates range between 85% and 92% for the coding region of the coat protein and 90% to 98% for the 3' non-coding region. Likewise, the region of the NIb gene sequenced shows 99% and 97% sequence identity in the deduced amino acid and the nucleotide sequences, respectively.
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Affiliation(s)
- A Mathews
- Centre for Legumes in Mediterranean Agriculture (CLIMA), Western Australian State Agricultural Biotechnology Centre, Murdoch University, Australia
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Abstract
The dynamic pattern of fetal breathing was studied in 17 fetal lambs with chronically implanted electromyographic electrodes in the diaphragm. The instantaneous breathing rate time series appeared similar on different time scales, with clusters of faster breathing rates interspersed with periods of relative quiescience, suggesting self-similarity. Distribution histograms of the interbreath intervals (IBIs) showed log-normal distribution for IBIs less than 1 s and inverse power-law distribution for IBIs greater than 1 s. The ratio of log-normal distribution to power-law distribution varied from approximately 2 at 102 days to approximately 30 by 130 days of gestation. Fast Fourier transform of the breathing rate time series revealed 1/f beta power spectra for all animals, with beta increasing linearly from 0.43 to 0.88 between 102 and 139 days. Studies in the newborn lamb showed further maturation in both the distribution characteristics of the IBIs, as well as in the 1/f power spectra, with beta approaching 1.0 at 2 days after birth. The inverse power-law relationship in the distribution of the IBIs, together with the 1/f beta power spectra, indicate scale invariance and suggest that fractal mechanisms are involved in the regulation of fetal breathing.
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Affiliation(s)
- H H Szeto
- Department of Pharmacology, Cornell University Medical College, New York, New York 10021
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Szeto HH, Cheng PY, Decena JA, Wu DL, Cheng Y, Dwyer G. Developmental changes in continuity and stability of breathing in the fetal lamb. Am J Physiol 1992; 262:R452-8. [PMID: 1558216 DOI: 10.1152/ajpregu.1992.262.3.r452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Developmental changes in the continuity and stability of fetal breathing patterns were studied in 27 fetal lambs with chronically implanted electromyographic electrodes in the diaphragm throughout the third trimester (102-140 days). The results showed that there was a progressive decrease in the incidence of fetal breathing movements throughout the third trimester (P less than 0.001). This reduction in incidence of fetal breathing movements was due, in part, to a 20% decrease in the total number of breathing bursts at approximately 125 days (P = 0.05). The breathing patterns in both immature (less than 120 days) and mature fetal lambs were fragmented by a large number of pauses (interburst interval 6-10 s) and apneas (interburst interval greater than 10 s). Increase in gestational age was associated with a decrease in the number of pauses and apneas but longer apnea durations. The breathing pattern in fetuses less than 120 days old was more continuous than that in those greater than 120 days old, as demonstrated by significantly longer epoch durations (P = 0.013). There was no significant change in the continuity of the breathing pattern after 120 days. However, there was a significant increase in the stability of the instantaneous breathing rates throughout the third trimester. This was indicated by a significant increase in the percent of breathing bursts that occurred in stable clusters (P = 0.046), the number of bursts per cluster (P = 0.013), and cluster duration (P = 0.018). Thus an increase in stability appears to be the major developmental change in breathing control in late gestation.
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Affiliation(s)
- H H Szeto
- Department of Pharmacology, Cornell University Medical College, New York, New York 10021
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Szeto HH, Cheng PY, Dwyer G, Decena JA, Wu DL, Cheng Y. Morphine-induced stimulation of fetal breathing: role of mu 1-receptors and central muscarinic pathways. Am J Physiol 1991; 261:R344-50. [PMID: 1652216 DOI: 10.1152/ajpregu.1991.261.2.r344] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The mechanism of action of low doses of morphine on breathing dynamics in the fetus was studied in 16 fetal lambs with chronically implanted electromyographic electrodes in the diaphragm. Morphine (0.15-2.5 mg/h) caused a significant dose-dependent increase in the number of diaphragmatic bursts per hour, with either an increase or no change in instantaneous breathing rate. There was also a significant dose-related increase in the continuity of the breathing pattern, as indicated by a decrease in the number of apneas per hour, and an increase in epoch duration. Morphine also had a significant effect on the stability of the breathing pattern, with an increase in the percentage of bursts that occurred in stable clusters. All of these effects were completely abolished by concurrent intracerebroventricular administration of either methylnaloxone or methylatropine or by pretreatment with intravenous naloxonazine. These results suggest that stimulation and stabilization of ventilatory activity in the fetal lamb by low doses of morphine are mediated via mu 1-receptors and involve central muscarinic pathways.
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Affiliation(s)
- H H Szeto
- Department of Pharmacology, Cornell University Medical College, New York, New York 10021
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Dwyer G, Whaley M, Murray K, Wallaco J, Miller W. 665 THE PREDICTION OF RESIDUAL VOLUME IN AN ADULT FITNESS POPULATION. Med Sci Sports Exerc 1990. [DOI: 10.1249/00005768-199004000-00664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Szeto HH, Zhu YS, Umans JG, Dwyer G, Clare S, Amione J. Dual action of morphine on fetal breathing movements. J Pharmacol Exp Ther 1988; 245:537-42. [PMID: 3367305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Morphine has been reported to both stimulate and suppress fetal breathing movements (FBM). In light of these conflicting reports, we have conducted a systematic dose-response analysis of the effects of morphine on FBM in 27 fetal lambs. Morphine was infused directly to the fetus in doses ranging from 0.075 to 80 mg/hr. Low doses (0.075-2.5 mg/hr) resulted in a progressive increase in the relative incidence of FBM, whereas higher doses (greater than 2.5 mg/hr) decreased FBM with total apnea observed at 80 mg/hr. This biphasic response can be fitted as the sum of two sigmoidal log dose-response curves. Both stimulation and suppression of FBM by morphine were abolished by naloxone pretreatment, indicating that both responses are mediated by activation of opioid receptors. The dual action of morphine on FBM may be due to different opioid receptor subtypes or different sites of action.
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Affiliation(s)
- H H Szeto
- Department of Pharmacology, Cornell University Medical College, New York, New York
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Abstract
A relatively powerful and inexpensive microcomputer-based system for the spectral analysis of the EEG is presented. High resolution and speed is achieved with the use of recently available large-scale integrated circuit technology with enhanced functionality (INTEL Math co-processors 8087) which can perform transcendental functions rapidly. The versatility of the system is achieved with a hardware organization that has distributed data acquisition capability performed by the use of a microprocessor-based analog to digital converter with large resident memory (Cyborg ISAAC-2000). Compiled BASIC programs and assembly language subroutines perform on-line or off-line the fast Fourier transform and spectral analysis of the EEG which is stored as soft as well as hard copy. Some results obtained from test application of the entire system in animal studies are presented.
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Szeto HH, Vo TD, Dwyer G, Dogramajian ME, Cox MJ, Senger G. The ontogeny of fetal lamb electrocortical activity: a power spectral analysis. Am J Obstet Gynecol 1985; 153:462-6. [PMID: 4050921 DOI: 10.1016/0002-9378(85)90088-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
With the use of a relatively inexpensive microcomputer-based system for power spectral analysis, we have been able to provide quantitative information on maturational changes in electrocorticogram waveforms in the third-trimester fetal lamb. Twenty-six electrocorticogram recordings were obtained from nine fetal lambs, with gestational ages ranging from 114 to 139 days' gestation. The transition from disorganized to cyclic electrocorticogram activity (high-voltage slow activity and low-voltage fast activity) occurred at approximately 115 to 120 days' gestation. However, quantitative changes in waveform characteristics of the electrocorticogram continued throughout the rest of gestation. These maturational changes occurred primarily in the low-voltage fast activity periods, with a decrease in power density in the delta (0.3 to 3 Hz) band and an increase in the maximum frequencies detected in the beta (15 to 30 Hz) band. There were no significant changes in the power spectrum of the high-voltage slow activity periods as a function of gestational age.
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